1. Field of the Invention
This invention relates to pyrimidine derivative compounds and pharmaceutically acceptable salts thereof. More specifically, this invention relates to furo[2,3-d]pyrimidines, pyrrolo[2,3-d]pyrimidines, pyrrolo[3,2-d]pyrimidines, pyrrolo[3,4-d]pyrimidines, thieno[2,3-d]pyrimidines, cyclopentapyrimidines and cyclopenta[d]pyrimidines. These compounds have been found useful in resisting and treating Pneumocystis carinii and Toxoplasmosis gondii infections in immunocompromised patients, such as, for example, patients with autoimmune deficiency syndrome (AIDS). These compounds are also useful as potential antitumor, antibiotic, antimalarial, antifungal or antiprotozoal agents, or as synergistic agents when used with sulfonamides may require the use of leucovorin rescue. These compounds are also useful as antitumor agents in cancer patients. Methods of preparing and using these compounds are also provided.
2. Description of the Background Art
Various pyrimidine systems, such as the pyrido[2,3-d]pyrimidine ring system, have been studied due to their involvement in the inhibition of dihydrofolate reductase (DHFR) enzymes activity. The pyrimidine derivatives disclosed herein function as DHFR inhibitors. Because DHFR reduces dihydrofolate to tetrahydrofolate, inhibition of DHFR deprives the cell of tetrahydrofolate, without which the cell cannot produce 5,10-Methylenetetrahydrofolate. 5,10-Methylenetetrahydrofolate is essential for cell growth. The inhibition of DHFR by the compounds, and pharmaceutically acceptable salts thereof, of this invention results in the inhibition of DNA synthesis and leads to cell death. Methotrexate (MTX), trimetrexate (TMQ), piritrexim (PTX) and other folic acid analogues function as inhibitors of cell growth by similar mechanisms involving the inhibition of dihydrofolate reductase.
The pyrimidine derivatives disclosed herein further function as thymidylate synthase (TS) inhibitors. TS, along with DHFR, forms part of the systems responsible for the synthesis of deoxythymidylate (dTMP) from deoxyuridylate (dUMP). TS catalyzes the sole de novo synthesis of dTMP from dUMP. Inhibition of TS, therefore, deprives the cell of thymidine, which is an essential constituent of DNA. Typically, the compounds as described herein where X and Y are both NH2 will function as DHFR inhibitors, and compounds where X is OH and Y is NH2 will function as TS inhibitors.
Drugs useful for the reduction of cancerous cells are also known.
Elslager, Edward F., et al., xe2x80x9cFolate Antagonists. 20. Synthesis and Antitumor and Antimalarial Properties of Trimetrexate and Related 6-[(Phenylamino)methyl]-2,4-quinazolinediaminesxe2x80x9d J. Med. Chem., Vol. 26 pp. 1753-1760 (1983)), discloses the preparation of quinazolinediamines. This article states that the quinazolinediamines exhibit potent antimalarial, antibacterial and antitumor activity.
Methods of synthesizing diaminopyrido[2,3-d]pyrimidines having various substituents are known. See Hurlbert, B. S., et al., xe2x80x9cStudies on Condensed Pyrimidine Systems. XXIII. Synthesis of 2,4-Diaminopyrido[2,3-d]pyrimidines from 6-Keto Estersxe2x80x9d, J. Med. Chem., Vol. 11, pp. 703-707 (1968), and Hurlbert, B. S., and Valenti, B. F., xe2x80x9cStudies on Condensed Pyrimidine Systems. XXIV. The Condensation of 2,4,6-Triaminopyridimine with Malondialdehyde Derivativesxe2x80x9d, J. Med. Chem., Vol. 11, pp. 708-710 (1968).
Hurlbert, B. S., et al., xe2x80x9cStudies on Condensed Pyrimidine Systems. XXV. 2,4-Diaminopyrido[2,3-d]pyrimidines. Biological Dataxe2x80x9d, J. Med. Chem., Vol. 11, pp. 711-717 (1968), discloses the antimicrobial activities of several subgroups of pyridopyrimidines. This article states that 2,4-diaminopyrido[2,3-d]pyrimidines bearing alkyl and aralkyl substituents in the pyrimidine moiety are inhibitors of dihydrofolate reductase having antibacterial and antiprotozoal activity and that these compounds potentiate sulfonamides.
Grivsky, E. M., et al., xe2x80x9cSynthesis and Antitumor Activity of 2,4-Diamino-6-(2,5-dimethoxybenzyl)-5-methylpyrido[2,3-d]pyridiminexe2x80x9d, J. Med. Chem., Vol. 23, pp. 327-329 (1980), discloses the synthesis of 2,4-diamino-6-(2,5-dimethoxybenzyl)-5-methylpyrido[2,3-d]pyridimine(BW301U,7). This article states that BW301U,7 is as effective as methotrexate as an inhibitor of dihydrofolate reductase purified from human leukemic cells and, in contrast to metoprine, has minimal activity as an inhibitor of histamine metabolism.
Werbel, Leslie, M., et al., xe2x80x9cSynthesis and Antimalarial Activity of a Series of 2,4-Diamino-6-[(N-alkylanilino)methyl]quinazolines [1,2]xe2x80x9d, J. Heterocyclic Chem., Vol. 24, pp. 345-349 (1987), discloses the synthesis of N6 substituted quinazoline dihydrofolate reductase inhibitors. This article states that these analogs demonstrate substantial activity against Plasmodium berghei infections in mice.
Piper, J. R., et al., xe2x80x9cSyntheses and Antifolate Activity of 5-Methyl-5-deaza Analogues of Aminopterin, Methotrexate, Folic Acid, and N10-Methylfolic Acidxe2x80x9d, J. Med. Chem., Vol. 29, pp. 1080-1087 (1986), discloses that 5-methyl-5-deaza analogues of aminopterin and methotrexate are much more growth inhibitory than methotrexate.
Pyrido[2,3-d] and [3,2-d]pyrimidines are also disclosed in U.S. Pat. Nos. 5,346,900 and 5,508,281, and co-pending application Ser. No. 08/515,491, all of which are hereby expressly incorporated by reference.
Pyrrolo[2,3-d]pyrimidines are disclosed by Gangjee et al. in xe2x80x9cNovel 2,4-diamino-5-substituted-pyrrolo[2,3-d]pyrimidines As Classical and Non-Classical Antifolate Inhibitors of Dihydrofolate Reductasesxe2x80x9d, J. Med. Chem., Vol. 38, pp. 2158-2165 (Jun. 6, 1995).
Gangjee, A., et al., xe2x80x9cClassical and Non-Classical Furo[2,3-d]Pyrimidines As Novel Antifolates: Synthesis and Biological Activitiesxe2x80x9d, J. Med. Chem., Vol. 37, pp. 1169-1176 (1994), discloses the furo[2,3-d]pyrimidines.
In spite of the art discussed above, there remains a very real and substantial need for compounds that are more active and more selective than known compounds at resisting and treating infections caused by Pneumocystis carinii and Toxoplasmosis gondii in immunocompromised patients, reducing the tumor size and/or the number of cancerous cells in cancer patients, and for methods of preparing and using such compounds.
The present invention has met the above described need. The present invention provides pyrrolo[2,3-d]pyrimidine compounds, and pharmaceutically acceptable salts thereof, having the formula (1): 
wherein X and Y are the same or different and are selected from the group consisting of OH and NH2;
wherein L and M are selected from the group consisting of carbon and CH, the chemical bond between L and M is selected from the group consisting of a single bond and a double bond, L and M are carbon when the bond is a double bond, and L and M are CH when the bond is a single bond;
wherein Z2 and Z3 are different and are selected from the group consisting of R4 and 
xe2x80x83where Z2 is R4 when 
xe2x80x83and Z2 is 
xe2x80x83when Z3 is R4;
wherein A is selected from the group consisting of CH and zero;
wherein B is selected from the group consisting of CH, nitrogen, Nxe2x80x94CH2, CH2xe2x80x94N, CH2xe2x80x94CH2, oxygen and sulfur;
wherein R1 is selected from the group consisting of hydrogen, a lower alkyl group, a nitroso group, a formyl group and zero and R1 is zero when B is oxygen or sulfur;
wherein R3 is selected from the group consisting of hydrogen, a lower alkyl group and zero, and R3 is zero when A is zero;
wherein R4 is selected from the group consisting of hydrogen and a lower alkyl group;
wherein R5 is selected from the group consisting of hydrogen and a lower alkyl group;
wherein R8 is selected from the group consisting of naphthyl, mono-, di- and tri-substituted naphthyl, thionaphthyl, thiophenyl and hydroxyphenyl when R1 is hydrogen and R4 is hydrogen;
wherein R8 is selected from the group consisting of phenyl, mono-, di- and tri-substituted phenyl, naphthyl, mono-, di- and tri-substituted naphthyl, pyridine and p-aroyl-L-glutamate when R1 is a lower alkyl group and R4 is hydrogen;
wherein R8 is selected from the group consisting of pyridine, phenyl, mono-, di- and tri-substituted phenyl, naphthyl, and mono-, di- and tri-substituted naphthyl and p-aroyl-L-glutamate when R1 is zero;
wherein R8 is selected from the group consisting of phenyl, mono-, di- and tri-substituted phenyl, naphthyl, mono-, di- and tri-substituted naphthyl and p-aroyl-L-glutamate when R1 is hydrogen and R4 is a lower alkyl group; and
wherein R8 is not p-benzoyl-L-glutamate or pyridine when X is OH, A is zero, B is sulfur, R4 is methyl and R5 is hydrogen, and R8 is not p-benzoyl-L-glutamate when X is OH, A is CH, B is CH, R4 is hydrogen and R5 is hydrogen; and
wherein each lower alkyl group is independently selected from the group consisting of lower alkyl groups having from 1 to 6 carbons.
The present invention also provides methods of synthesizing pyrrolo[2,3-d]pyrimidine compounds, and pharmaceutically acceptable salts thereof, having the formula (2): 
wherein R is selected from the group consisting of a lower alkyl group, a p-aroyl-L-glutamate group, an aryl group, an alkylaryl group, a substituted aryl group, a substituted alkylaryl group, a diaryl group, a triaryl group, an alkyldiaryl group, an alicyclic hydrocarbon group, an alkyltriaryl group, a substituted diaryl group, and a substituted triaryl group, and each substituent of the substituted aryl group, diaryl group, triaryl group, or the substituted alkylaryl group, alkyidiaryl group, alkyltriaryl group is the same or different and is selected from the group consisting of a lower alkyl group, an alkoxy, a substituted alkoxyaryloxy group and a halogen; and
wherein each lower alkyl group is independently selected from the group consisting of lower alkyl groups having from about 1 to 6 carbons, comprising the steps of:
a) denominating a pyrrole;
b) fusing the product of step a) with an amidine;
c) condensing the product of step b) with a nucleophile,
d) reducing the product of step c); and
e) purifying the compounds of step d).
The present invention also provides furo[2,3-d]pyrimidine compounds, and pharmaceutically acceptable salts thereof, having the formula (4): 
wherein X and Y are the same or different and are selected from the group consisting of OH and NH2;
wherein L and M are selected from the group consisting of carbon and CH, the chemical bond between L and M is selected from the group consisting of a single bond and a double bond, L and M are carbon when the bond is a double bond, and L and M are CH when the bond is a single bond;
wherein Z and Z1 are different and are selected from the group consisting of R4 and 
xe2x80x83where Z is R4 when 
xe2x80x83Z is 
xe2x80x83Z1 is R4;
wherein A is selected from the group consisting of CH and zero;
wherein B is selected from the group consisting of sulfur, nitrogen, oxygen, CH, Nxe2x80x94CH2, CH2xe2x80x94N, CH2xe2x80x94CH2, and zero;
wherein R1 is selected from the group consisting of hydrogen, a lower alkyl group, a nitroso group, a formyl group and zero and R1 is zero when B is sulfur, oxygen or zero;
wherein R2 is selected from the group consisting of a lower alkyl group, p-aroyl-L-glutamate, an aryl group, an alkylaryl group, a substituted aryl group, a substituted alkylaryl group, a diaryl group, a triaryl group, an alkyldiaryl group, an alicyclic hydrocarbon group, an alkyltriaryl group, a substituted diaryl group, and a substituted triaryl group, and each substituent of the substituted aryl group, diaryl group, triaryl group, or the substituted alkylaryl group, alkyldiaryl group, alkyltriaryl group is the same or different and is selected from the group consisting of a lower alkyl, an alkoxy, an alkoxyaryloxy group, a halogen and zero but R2 is not 3,4,5-trimethoxyphenyl, 3,4,5-trichlorophenyl, 3,4-dichlorophenyl, 2,5-dimethoxyphenyl or a p-benzoyl-L-glutamate when R1 is hydrogen and R4 is hydrogen, and R2 is not p-benzoyl-L-glutamate when R1 is methyl;
wherein R3 is selected from the group consisting of hydrogen, a lower alkyl group, and zero and R3 is zero when A is zero;
wherein R4 is selected from the group consisting of hydrogen, a lower alkyl group and Sxe2x80x94R7 where R7 is selected from the group consisting of phenyl, mono-, di- and tri-substituted phenyl, naphthyl, mono-, di- and tri-substituted naphthyl and p-aroyl-L-glutamate; and
wherein each lower alkyl group is independently selected from the group consisting of lower alkyl groups having from 1 to 6 carbons.
The present invention also provides thieno[2,3-d]pyrimidine compounds, and pharmaceutically acceptable salts thereof, having the formula (5): 
wherein X and Y are the same or different and are selected from the group consisting of OH and NH2;
wherein L and M are selected from the group consisting of carbon and CH, the chemical bond between L and M is selected from the group consisting of a single bond and a double bond, L and M are carbon when the bond is a double bond, and L and M are CH when the bond is a single bond;
wherein Z and Z1 are different and are selected from the group consisting of R4 and 
xe2x80x83where Z is R4 when 
xe2x80x83and Z is 
xe2x80x83when Z1 is R4;
wherein A is selected from the group consisting of CH and zero;
wherein B is selected from the group consisting of sulfur, nitrogen, oxygen, CH, Nxe2x80x94CH2, CH2xe2x80x94N, CH2xe2x80x94CH2, and zero;
wherein R1 is selected from the group consisting of hydrogen, a lower alkyl group, a nitroso group, a formyl group and zero and R1 is zero when B is sulfur, oxygen or zero;
wherein R2 is selected from the group consisting of a lower alkyl group, an aryl group, p-aroyl-L-glutamate, an alkylaryl group, a substituted aryl group, a substituted alkylaryl group, a diaryl group, a triaryl group, an alkyldiaryl group, an alicyclic hydrocarbon group, an alkyltriaryl group, a substituted diaryl group, and a substituted triaryl group, and each substituent of the substituted aryl group, diaryl group, triaryl group, or the substituted alkylaryl group, alkyldiaryl group, alkyltriaryl group is the same or different and is selected from the group consisting of a lower alkyl group, an alkoxy, an alkoxyaryloxy group, a halogen and zero;
wherein R3 is selected from the group consisting of hydrogen, a lower alkyl group and zero, and R3 is zero when A is zero;
wherein R4 is selected from the group consisting of hydrogen and lower alkyl group; and
wherein each lower alkyl group is independently selected from the group consisting of lower alkyl groups having from about 1 to 6 carbons.
The present invention also provides pyrrolo[3,2-d]pyrimidine compounds, and pharmaceutically acceptable salts thereof, having the formula (6): 
wherein X and Y are the same or different and are selected from the group consisting of OH and NH2;
wherein L and M are selected from the group consisting of carbon and CH, the chemical bond between L and M is selected from the group consisting of a single bond and a double bond, L and M are carbon when the bond is a double bond, and L and M are CH when the bond is a single bond;
wherein Z and Z1 are different and are selected from the group consisting of R4 and 
xe2x80x83where Z is R4 when 
xe2x80x83and Z is 
xe2x80x83when Z1 is R4;
wherein A is selected from the group consisting of CH and zero;
wherein B is selected from the group consisting of sulfur, nitrogen, oxygen, CH, Nxe2x80x94CH2, CH2xe2x80x94N, CH2xe2x80x94CH2, and zero;
wherein R1 is selected from the group consisting of hydrogen, a lower alkyl group, a nitroso group, a formyl group and zero, and R1 is zero when B is sulfur, oxygen or zero;
wherein R2 is selected from the group consisting of a lower alkyl group, p-aroyl-L-glutamate, an aryl group, an alkylaryl group, a substituted aryl group, a substituted alkylaryl group, a diaryl group, a triaryl group, an alkyldiaryl group, an alicyclic hydrocarbon group, an alkyltriaryl group, a substituted diaryl group, and a substituted triaryl group, and each substituent of the substituted aryl group, diaryl group, triaryl group, or the substituted alkylaryl group, alkyldiaryl to group, or alkyltriaryl group is the same or different and is selected from the group consisting of a lower alkyl group, an alkoxy, an alkoxyaryloxy group, a halogen and zero;
wherein R3 is selected from the group consisting of hydrogen, a lower alkyl group and zero, and R3 is zero when A is zero;
wherein R4 is selected from the group consisting of hydrogen and lower alkyl group;
wherein R5 is selected from the group consisting of hydrogen and lower alkyl group; and
wherein each lower alkyl group is independently selected from the group consisting of lower alkyl groups having from about 1 to 6 carbons.
The present invention also provides pyrrolo[3,4-d]pyrimidine compounds, and pharmaceutically acceptable salts thereof, having the formula (7): 
wherein X and Y are the same or different and are selected from the group consisting of OH and NH2;
wherein A is selected from the group consisting of CH and zero;
wherein B is selected from the group consisting of sulfur, nitrogen, oxygen, CH, Nxe2x80x94CH2, CH2xe2x80x94N, CH2xe2x80x94CH2, and zero;
wherein R1 is selected from the group consisting of hydrogen, a lower alkyl group, a nitroso group, a formyl group and zero and R1 is zero when B is sulfur, oxygen or zero;
wherein R2 is selected from the group consisting of a lower alkyl group, p-aroyl-L-glutamate, an aryl group, an alkylaryl group, a substituted aryl group, a substituted alkylaryl group, a diaryl group, a triaryl group, an alkyldiaryl group, an alicyclic hydrocarbon group, an alkyltriaryl group, a substituted diaryl group, and a substituted triaryl group, and each substituent of the substituted aryl group, diaryl group, triaryl group, or the substituted alkylaryl group, alkyldiaryl group, or alkyltriaryl group is the same or different and is selected from the group consisting of a lower alkyl group, an alkoxy, an alkoxyaryloxy group, a halogen and zero;
wherein R3 is selected from the group consisting of hydrogen, a lower alkyl group, and zero, and R3 is zero when A is zero;
wherein R4 is selected from the group consisting of hydrogen and lower alkyl group; and
wherein each lower alkyl group is independently selected from the group consisting of lower alkyl groups having from about 1 to 6 carbons.
The present invention also provides cyclopentapyrimidine and cyclopenta[d]pyrimidine compounds, and pharmaceutically acceptable salts thereof, having the formula (8): 
wherein X and Y are the same or different and are selected from the group consisting of OH and NH2;
wherein L and M are selected from the group consisting of carbon and CH, the chemical bond between L and M is selected from the group consisting of a single bond and a double bond, L and M are carbon when the bond is a double bond, and L and M are CH when the bond is a single bond;
wherein Z4, Z5 and Z6 are different and are selected from the group consisting of R4, R5 and 
wherein A is selected from the group consisting of CH, sulfur and zero;
wherein B is selected from the group consisting of sulfur, nitrogen, oxygen, CH, Nxe2x80x94CH2, CH2xe2x80x94N, CH2xe2x80x94CH2, and zero;
wherein R1 is selected from the group consisting of hydrogen, a lower alkyl group, a nitroso group, a formyl group and zero, and R1 is zero when B is sulfur, oxygen or zero;
wherein R2 is selected from the group consisting of a lower alkyl group, p-aroyl-L-glutamate, an aryl group, an alkylaryl group, a substituted aryl group, a substituted alkylaryl group, a diaryl group, a triaryl group, an alkyldiaryl group, an alicyclic hydrocarbon group, an alkyltriaryl group, a substituted diaryl group, and a substituted triaryl group, and each substituent of the substituted aryl group, diaryl group, triaryl group, or the substituted alkylaryl group, alkyldiaryl group, or alkyltriaryl group is the same or different and is selected from the group consisting of a lower alkyl group, an alkyl group, an alkoxy, an alkoxyaryloxy group, a halogen and zero;
wherein R3 is selected from the group consisting of hydrogen, a lower alkyl group and zero, and R3 is zero when A is zero;
wherein R4 is selected from the group consisting of hydrogen and a lower alkyl group;
wherein R5 is selected from the group consisting of hydrogen and a lower alkyl group;
where R4 is the same or different than R5;
wherein each of said R4, R5 and 
xe2x80x83substituents is used once; and
wherein each lower alkyl group is independently selected from the group consisting of lower alkyl groups having from about 1 to 6 carbons.
Methods of synthesizing the above compounds are also disclosed.
As used herein, the term xe2x80x9cpharmaceutically acceptable saltsxe2x80x9d includes, but is not limited to, acetate, formate, glucuronate, ethantate, sulfonate, or other salts known to those skilled in the art.
In formulas 1 and 4-9, when X and Y are the same or different and are selected from the group consisting of OH and NH2 groups, the enol form of the compounds is represented. The enol form is equivalent to and includes the keto form of the compounds.
As used herein, the term xe2x80x9clower alkyl groupxe2x80x9d refers to an alkyl group having between 1 and 6 carbons. The number of carbons in each lower alkyl group in each of formulas 1-9 can vary. For example, with reference to Formula 4, R1 could represent a lower alkyl group having 1 carbon, R2 could represent a lower alkyl group having 2 carbons, R3 could represent a lower alkyl group having 3 carbons, and R4 could represent a lower alkyl group having 4 carbons.
As will be understood one skilled in the art, when any of the variables used herein equal zero, that variable is not present in a particular embodiment of the general formula. In any of the above described formulas, when A equals zero, R3 also equals zero, and B is either zero or is attached directly to L. When B is zero, R1 also equals zero, and R2 and R8 are either zero or are attached directly to A. When both A and B are zero, R1 and R3 are also zero and R2 and R8 are either zero or is attached directly to L.
As used herein, the term aroyl, such as for example when used within the term p-aroyl-L-glutamate, refers to heteroaroyl, benzoyl, napthoyl, thiophenoyl, furophenoyl, pyrroyl, and any other aroyl as that term would be understood by one skilled in the art.
This invention also provides methods for therapeutically and/or prophylactically using the compounds, and pharmaceutically acceptable salts thereof, described herein.
This invention provides a method of using the pyrimidine derivatives of Formulas 1, 2 and 4-9 described herein for therapeutic and prophylactic purposes including employing these compounds to resist and treat secondary infections caused by Pneumocystis carinii and Toxoplasmosis gondii or other organisms in immunocompromised patients, such as for example patients with AIDS. The immunocompromised patient has a primary infection caused by a retrovirus, including for example, human immunodeficiency virus (HIV). In addition, this invention provides methods of using pyrimidine derivatives as antitumor, antibiotic, antimalarial, antifungal and antiprotozoal agents and as synergistic agents with sulfonamides in such patients.
This invention also provides methods of using pyrimidine derivatives for therapeutic purposes as antitumor agents or to otherwise destroy cancerous cells in cancer patients.
It is an object of this invention to provide pyrimidine derivative compounds, and pharmaceutically acceptable salts thereof, for substantially inhibiting dihydrofolate reductase enzymes.
It is an object of this invention to provide pyrimidine derivative compounds, and pharmaceutically acceptable salts thereof, for substantially inhibiting thymidylate synthase enzymes.
It is an object of the present invention to provide pyrimidine derivative compounds, and pharmaceutically acceptable salts thereof, having antitumor, antibiotic, antimalarial, antifungal or antiprotozoal activity or synergistic activity with sulfonamides.
It is a further object of this invention to provide pyrimidine derivative compounds, and pharmaceutically acceptable salts thereof, having effective activity against secondary infections, such as for example infections caused by Pneumocystis carinii and Toxoplasmosis gondii that occur in immunocompromised patients, such as for example patients with AIDS.
It is another object of this invention to provide pyrimidine derivative compounds, and pharmaceutically acceptable salts thereof, having effective activity against tumors and other cancerous cells, such as those caused by cancer.
It is an object of this invention to provide a method of synthesizing various pyrimidine derivative compounds, and pharmaceutically acceptable salts thereof.
It is a further object of this invention to provide methods of using in a patient a therapeutically effective amount of pyrimidine derivative compounds, or pharmaceutically acceptable salts thereof.
It is a further object of this invention to provide methods of using in a patient a prophylactically effective amount of pyrimidine derivative compounds, or pharmaceutically acceptable salts thereof.
These and other objects of the invention will be more fully understood from the drawing and the following description of the invention and the claims appended hereto.